Lost Ball... A bit of help Please

[bill south]

While dissassembling my Nook SBN7201 3/4" ballnuts for cleaning prior to installation in my X axis home brew, I witnessed a bit of magic!!!! It happened like this! I carefully dissassembled the ball nut by removing the cardboard tube (easy) with the assembly held over a tub. The tub was designed to catch all the little critter balls. Well, one jumped out of the tub and bounced across my shop concrete floor. Now the magic. It has totally disappeared. Like I said, magic.
Well, I called Nook and the very helpful representative said that all seventy balls must be in place. In addition, I mentioned to him that the spec for the balls were .140 and I'm measureing .138 for all the remaining critters. Some precision huh???
Well, to make a long story short the Nook representative told me to source a replacement ball from (get this), a local hardware store. Well he's the expert so I thanked him and disconnected. Well, guess what?? (sorry, redneck in me). I checked with Lowes, Ace Hardware, True Value, the bodunk seed and feed, and Home Depot and noone carries replacment ball nut balls. Go figure.
Sooooooooooo, what will be the impact of using only 69 balls. In my configuration, each screw will have two ball nuts on it with a tensioning device for taking out the backlash. Any help will be appreciated.
Signed: dumbasmud!
billyjack

[mxtras]

I doubt you would ever be able to tell that one ball was missing.

Scott

[NC Cams]

At some point, you might feel a jerk or momentary sticking in the motion.

We did the "one missing won't matter" deal and that's what happens on occasion.

Try doing a site search for "oversize ball". Someone posted the name of a company that sells balls of nearly any size at a very reasonable price. You may have to meet a minimum buy but "magic" teaches you things like that at times.

[kaye7877]

McMaster Carr has .1406 balls for $4+ per pack of 100 if you really would like to replace it and you think this size would work. They also have 3.5mm(.138) ball. Which one do you have?

Sometimes, bearing manufactures sort balls and match them to the appropriate ball screw/nut combo. I have no idea if all manufacturers do it, but I know it happens. Maybe the companies can make the parts cheaper without the super tight tolerances, so they just sort the parts and put the right balls with the right components. So, you might carefully measure a few balls and try to match the size closely.

[RonDre]

Ebay has listings for replacement balls for ballscrews.

[eman5oh]

http://www.salemball.com/

Originally Posted by NC Cams At some point, you might feel a jerk or momentary sticking in the motion. We did the "one missing won't matter" deal and that's what happens on occasion. Try doing a site search for "oversize ball". Someone posted the name of a company that sells balls of nearly any size at a very reasonable price. You may have to meet a minimum buy but "magic" teaches you things like that at times.

[widgitmaster]

Just out of curiosity, I measured the balls in a 5/8-5 Nook ball nut with my electronic micrometer (.00005 accuracy)

The balls measured from .12455 to .12450

I have a serious collection of balls left over from projects over the years, if you can be more specific of the ball diameter, I will look through them for a match for you! Most of the balls are high-grade Deltronics inspection grade!

Just a thought!
Eric

[Mr.Chips]

At least some ACE Hardware stores have loose ball bearings, I know I have baught them for various projects. They are in the little metal cabnets each having about 4 or 5 drawers, with all the speciality hardware section. Just take your mic. and check yourself most people in the stores now have no idea what they do have.

Good Luck
Hager

[Willbird]

Where did you get your nook ballscrew nut Bill ?? Are you using two of the non preloaded ones opposed to take out backlash ?? I just bought 72" of nook precision rolled ballscrew and will need some nuts.

[widgitmaster]

HOMESHOPCNC

[Willbird]

All he lists is 5/8" and he referred me to Mcmaster for bigger stuff ??

[cncuser1]

Originally Posted by bill south While dissassembling my Nook SBN7201 3/4" ballnuts for cleaning prior to installation in my X axis home brew, I witnessed a bit of magic!!!! It happened like this! I carefully dissassembled the ball nut by removing the cardboard tube (easy) with the assembly held over a tub. The tub was designed to catch all the little critter balls. Well, one jumped out of the tub and bounced across my shop concrete floor. Now the magic. It has totally disappeared. Like I said, magic. Well, I called Nook and the very helpful representative said that all seventy balls must be in place. In addition, I mentioned to him that the spec for the balls were .140 and I'm measureing .138 for all the remaining critters. Some precision huh??? Well, to make a long story short the Nook representative told me to source a replacement ball from (get this), a local hardware store. Well he's the expert so I thanked him and disconnected. Well, guess what?? (sorry, redneck in me). I checked with Lowes, Ace Hardware, True Value, the bodunk seed and feed, and Home Depot and noone carries replacment ball nut balls. Go figure. Sooooooooooo, what will be the impact of using only 69 balls. In my configuration, each screw will have two ball nuts on it with a tensioning device for taking out the backlash. Any help will be appreciated. Signed: dumbasmud! billyjack

I had great servicce from salem ball.
Make verrrrry precise measurements of one, or a few of your existing balls.
Use a VERRRY precise micrometer ( to four decimal places). A vernier caliper is not precise enough in my opinion.